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ORCHID FAMILY (ORCHIDACEAE).

This is one of the most interesting of the plant families found in Mt. Rainier National Park due to the highly specialized nature of the flowers, which are so constructed that they are practically dependent upon insects for pollinization. The flower has a very peculiar form, having three sepals and three petals, one of which is usually developed into a sac or spur called the "lip". This accounts for such oddly formed flowers as the Lady Slipper. The stamens and pistil are united into a single column and the pollen is massed into two pear-like units, called pollinia, which are attached by stalks to a sticky disk. When an insect visits the flower in search of nectar, this entire unit sticks to its head or body. Twelve species of orchids are native to the park. A key to the genera follows.

COMMON PLANTS OF THE ORCHID FAMILY. (ORCHIDACEAE).
(1) White Swamp Orchis (Habenaria dilatata var. leucostachys). (2) Ladyslipper (Calypso bulbosa). (3) Coral Root (Corallorhiza mertensiana).

Coral Root (Corallorhiza mertensiana). This, the most common of three local species in this genus, all of which are saprophytic or parasitic on the roots of other plants, is usually found growing in small colonies in the duff of the deep forest up to 3500 or 4000 ft. in elevation. The entire plant stem, bract-like leaves and flowers - is coral-red in color. The plant grows to a height of 4-16 inches and the small, spurred flowers, 10-20 in number, are borne in a terminal raceme. Another species (Coral lorhiza maculata) may also be found quite often in similar situations but in this case the plant is sometimes yellowish, is not generally as tall as C. mertensiana and the lip of the flower is spotted with crimson. A third species (Corallorhiza striata) is more often encountered in dry woods. Its flowers do not possess a spur and the sepals are characterized by three conspicuous veins. The common name of "coral root" applies alike to all three species, all having masses of much-branched coral-like roots.

Phantom Orchid (Cephalanthera austinae). This is a very rare plant of the deep woods. It is entirely white and waxy in appearance, 6-15 inches tall. The flowers are erect in a terminal raceme, 3-20 in number and almost sessile.

Ladyslipper (Calypso bulbosa). This is one of the most beautiful plants of the lower elevations. The flower stem is but 2-5 inches long, wrapped at the base by several scales, and bearing at the apex a single slipper-like flower. The petals are light purple in color, spreading and lanceolate in outline; the slipper-like form of the flower is due to the peculiar shape of the lip. A tuft of yellow hairs is within the slipper-like lip. While not rare this plant is not widely distributed, being found in the early summer in moist soils of the dense woods at the lower elevations (up to about 2500 feet in elevation). See illustration on page 53.

Tway Blade (Listera sp.). There are two species of this genus native to the park and both are common in the moist soils of the deep woods at the lower elevations. The single pair of broad, opposite leaves, borne about midway on the stem, readily characterizes either of these plants.

Listera caurina is the more common of the two species. It is 3-12 inches tall with small spurless flowers upon slender pedicels borne in a terminal raceme. The other species, known as the Heart-leaved Twayblade (Listera cordata) may be readily distinguished by the cordate (heart-shaped at the base) leaves.

White Swamp Orchis (Habenaria dilatata var. leucostachys). This plant is quite common in marshy situations at the lower elevations of the park, such as in the swampy meadow about the mineral springs at Longmire. The stout, hollow stems, 10-30 inches tall, bear numerous white flowers about 1/2 inch long in a handsome terminal, compact spike. The numerous leaves are linear-lanceolate in outline and from 3-8 inches long.

Green Swamp Orchis (Habenaria saccta). This plant also prefers very moist soils but is more common in the Hudsonian zone. The flowers, borne in a terminal spike, are green, and largely because of this the plant is not as handsome as the white swamp orchis of the lower elevations. The leaves are oblong-lanceolate in outline.

Swamp Orchis (Habenaria unalaschensis). The leaves of this species are mainly basal, those on the stem being reduced to mere bracts. The leaves, usually 2-3 in number are oblanceolate in outline, obtuse and about six inches long. These generally wither before the flowers bloom. The flowers are small, greenish and borne in a spike.

Rattlesnake Plantain (Peramium decipiens). A very common plant of moist soils in the deep woods. The leaves, ovate in outline, and arranged in a flat rosette on the ground at the base of the flower stalk, are characterized by a whitish or cream-colored stripe down the middle, which is an excellent character for field identification. The flower stalks are erect and from 6-12 inches tall. The flowers are compacted upon short bracted, one-sided spikes, from 2-4 inches long.

Spiranthes (Spiranthes romanzoffiana). The spirally twisted raceme of whitish yellowish flowers readily identifies this plant. It is from 3-16 inches tall with leaves at the lower portion of the stem oblong-lanceolate to linear in outline, and those on the upper portion of the stem scale-like.

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Descriptions continued...